Construction of a Unique Structure of Ru Sites in the RuP Structure for Propane Dehydrogenation

It is an important task to develop low-cost and anticoking catalysts for the propane dehydrogenation (PDH) reaction. In this work, the P element is introduced to the Ru-based catalyst to obtain Ru sites with a unique structure and the obtained RuxPy (x/y = 2:1, 1:1, 1:2) catalysts are then employed in PDH. Density functional theory (DFT) results show that the addition of P leads to the formation of separated Ru sites and the adjustment of the valance band state of Ru. The upward shift of the d-band center leads to a reduction of the reaction energy barrier for dehydrogenation of propane and an enhancement of catalytic activity. The analysis of the competition between propylene deep dehydrogenation and propylene desorption for each catalyst shows that desorption of propylene is preferred on the RuP(112) surface. Considering both catalytic activity and propylene selectivity, the RuP catalyst is potential for the propane dehydrogenation reaction. On the RuP surface, the PDH reaction proceeds by the dehydrogenation of the H atom on the methylene group (isopropyl pathway), thus restraining the deep dehydrogenation of propylene. The RuxPy catalysts are also synthesized in experiments, and PDH evaluation shows that the RuP structure is a remarkable PDH catalyst with a stable structure, anticoking ability, and low cost.

Automated summary

Developing low-cost and anticoking catalysts for propane dehydrogenation (PDH) is crucial. The addition of P element to Ru-based catalyst in this study leads to the formation of unique Ru sites, increasing catalytic activity and decreasing the energy barrier for the PDH reaction. The RuP catalyst shows potential for PDH with its ability to restrain deep dehydrogenation of propylene and high propylene selectivity.